There are two ways to abbreviate "Sunday": Long abbreviation (Sun.) and Short abbreviation (S/U).
There are two basic ways to abbreviate "Sunday":
Long abbreviation (Sun.)
We met Olivia's sister last Sun.
Short abbreviation (S or U)
Next conference on S
These abbreviations are quite common in American, Australian, Canadian, and British English. However, use the shortest form only if space is limited, for example, when writing quick notes or using tables, charts, or illustrations.
We enjoyed a delicious dinner last Sun.
Team meeting on S.
And ensure it is obvious to users which day you are referring to.
Her son was born last U.
Her son was born last Sun.
Do we need a period after Sun? MLA style recommends adding a period if the abbreviation ends in a lowercase letter (e.g., Sun.) By contrast, if the abbreviation is composed solely of capital letters, such as S or U, we should omit the period.
The match will be played on Sun./S/U in Chicago.
And remember, we always capitalize Sunday, even if this noun is abbreviated.
On Sun., Olivia went to the park with her friends.
On sun., Olivia went to the park with her friends.
Follow these abbreviation rules with the rest of the days of the week: